#include <iostream>
using namespace std;

#define MAXSIZE 50
typedef int ElemType;
typedef  struct
{
  ElemType  *R; 
  int  length;
} SSTable;  
int  Search_Bin(SSTable T, ElemType k)
{  
    int low,high,mid;
    low=1;
    high=T.length;
    while ( low < high )
    {  
        mid=low + high / 2 ;
        if (T.R[mid] == k)  
            return  mid;
        else  if (k< T.R[mid])   
            high=mid;
        else   
            low=mid+1;
   }
   return 0 ;
}
int main ()
{  SSTable T;  ElemType k;
   Create(T);
   cin>>k;
   int pos=Search_Bin(T,k);
   if(pos==0) cout<<"NOT FOUND"<<endl;
   else cout<<pos<<endl;
   return 0;
}

